Flying teams of interventionists directly to a primary stroke centre to perform endovascular therapy (EVT)—as opposed to waiting for the patient to be transferred to an intervention centre—may be associated with a higher probability of receiving EVT, a reduced time to treatment of roughly 90 minutes, comparable complication rates and slightly improved functional outcomes at three months. This is according to Gordian Hubert, a senior physician in the Department of Neurology and Neurological Intensive Care Medicine at the Munich Harlaching Clinic and head of the TEMPiS (Telemedical Stroke Network Southeast Bavaria) project (Munich, Germany), who presented data from a prospective study carried out in the TEMPiS network at the 7th European Stroke Organisation Conference (ESOC 2021; 1–3 September, virtual).
“As we all know, the effect of endovascular treatment is highly time dependent, and we also know that intervention expertise is scarce in rural areas—meaning rural patients experience significant treatment delays and worse outcomes,” Hubert stated. He went on to describe a new approach to treating these stroke patients, which involves a flying intervention team (FIT) travelling directly via helicopter to a primary stroke centre to perform EVT. This differs from the standard model of care whereby patients are transferred from the site of stroke onset to a primary stroke centre for diagnosis, and then transferred on to an intervention centre later to undergo a thrombectomy.
He claimed that, in addition to removing the need to prepare patients for transfer to a separate intervention centre, and cutting out the time spent admitting patients to the new centre, a key reason why the FIT approach is so much faster than conventional methods is because it allows transportation of the FIT and preparation of the patient for surgery to be done simultaneously. “That allows you to move the start of the therapy forward, and that is where you really gain time,” Hubert stated. “The parallelisation of processes is what really makes the difference here.”
To assess this novel approach, Hubert and his colleagues conducted a prospective cohort study within the TEMPiS network in Germany between February 2018 and January 2021. A total of 15 primary stroke centres participated in the study. Hubert reported that two FITs were available for half of the study period, with the standard model of interhospital transfer being used throughout the other half. This led to 134 EVT-eligible patients (57% female, average age=75 years) being treated with FIT and 210 EVT-eligible patients (47% female, average age=76 years) being treated following transfer.
Hubert noted that, in the study, when FIT was deployed, patients received EVT 84% of the time—compared to just 65% when they were transferred for the procedure instead. He added that the median time taken to decide on a treatment was 62 minutes in the FIT group and 148 minutes in the transfer group, which he described as “highly statistically significant”. And, while successful recanalisation was more even between the two groups, being achieved 94% of the time in the FIT group and 88% of the time in the transfer group, the median time from stroke onset to recanalisation—the “most important” time metric from the patient’s point of view, according to Hubert—was 240 minutes in the FIT group and 338 minutes in the transfer group.
Regarding safety outcomes, mortality within three months, and in-hospital and periprocedural complications, were all similar between the two groups. Discussing the study’s primary endpoint—functional outcome, as measured by modified Rankin Scale (mRS) scores, at three months—Hubert noted that, while there was a trend towards better outcomes in the FIT group, an ordinal logistic regression analysis revealed that this did not reach statistical significance.
He went on to state that, for various reasons, a large number of patients ultimately did not receive EVT within the study and, as such, the researchers carried out a subgroup analysis looking solely at patients who received EVT. “Obviously, those are the ones that may benefit from shorter time delays,” Hubert told the audience. Once again, this subgroup analysis revealed a similar trend towards improved three-month outcomes in the FIT group, but not to a statistically significant extent.
Hubert closed his presentation by highlighting several limitations of the study, including its observational design, which may have created a risk of systemic biases, as well as the difficulties in comparing an existing, unaltered healthcare structure with a novel system of care. He noted that the mono-regional design of the study could also be seen to harm the generalisability of its data. “We need more research and we need more data from other groups setting this up in their regions to really know whether we can spread this model of care—and whether it is worthwhile for our patients,” he concluded.